C++ to WebAssembly conversions

This page shows what is automatically translated and to what. On the left is the C++ and to the right what the corresponding interface in javascript will be. Not converted means there will be no automatic translation to a corresponding javascript object. Note that any restriction this poses only applies to the public interface of your code (e.g. your public headers).

Conversion tables

C++	WebAssembly translation
Namespace	Object namespace
Nested namespace	Nested object namespace
Class	Class
Public function	Class function
Private function	Not converted
Virtual function	Overridable function
Static member function	Static class function
Static member variable	Static member variable
Public const member variable	Read only property
Public non const member variable	Read write property
Private member variable	Not converted
Global variable	Module variable
Global static variable	Module variable
Free function	Module function
Overloaded function	Module function*
Enum	Enum
Scoped enum	Enum
Templated class/function	Not converted**
Specialized class template	Class***
Specialized function template	Function****

* Changes the name of the function based on the arguments to avoid clashes.

** No direct translation to javascript. Will not emit warning.

*** The naming convention for these classes can be found under the Template Naming Convention page.

**** Functions with different template arguments will behave as overloaded functions.

C++ Standard library class	WebAssembly translation
std::array	array
std::complex	???
std::deque	???
std::filesystem::path	???
std::forward_list	Not converted
std::function	???
std::list	???
std::map	Map Object*
std::multimap	Not converted
std::multiset	Not converted
std::optional	???
std::pair	array
std::priority_queue	Not converted
std::queue	Not converted
std::set	???
std::shared_ptr	???
std::stack	Not converted
std::tuple	???
std::unique_ptr	Value**
std::shared_ptr	Value
std::unordered_map	???
std::unordered_multimap	Not converted
std::unordered_multiset	Not converted
std::unordered_set	???
std::valarray	???
std::variant	???
std::vector	Vector Object***

* Converted via the register_map function (behaves like an Object in javascript).

** Note that arguments of type unique_ptr<T> are not supported. For more info see here.

*** Converted via the register_vector function (behaves like an Object in javascript).

C++ builtin type	WebAssembly translation
bool	true
char	Number
char16_t	Number
char32_t	Number
double	Number
float	Number
int	Number
int8_t	Number
int16_t	Number
int32_t	Number
int64_t	Number
long double	Number
long int	Number
long long int	Number
short int	Number
signed char	Number
string	ArrayBuffer, Uint8Array, Uint8ClampedArray, Int8Array, or String
string_view	String*
uint8_t	Number
uint16_t	Number
uint32_t	Number
uint64_t	Number
unsigned char	Number
unsigned int	Number
unsigned long int	Number
unsigned long long int	Number
unsigned short int	Number
wchar_t	Number

* Only works for globals (see examples)